Maybe this project has been asked many times.
I have a real problem. My kids like biking around the house. But there are blind angles where they cannot realize if a vehicle is approaching or not. So, the risk of an impact is high.
I would make a system to alert them when a vehicle is approaching the street on the blind side.
Let assume that the street on the blind side is 50m long. So it would be great if I can detect the vechicle when it enters the street.
So, I think I need:
A detection system of the vechicle in the range of 50 m from the measurement point
A gateway to transmit the alert
A receiver mounted on the bikes
I could use Arduino zero for the bike connected to some RF modules (Xbee? LF modules?)
The hard part is to choose the detection system.
I have these options.
Microwave radar: many commercial sensors are Dopple radar so we need prost-processing. Flase positives are high.
Optical radars. Without using laser, it is quite hard to reach long distance.
Ultrasound. Similarly, commercial ultrasound sensors have a range of 4meters max.
Image processing -> forget Arduino
What do you suggest?
Maybe I can throw away the requirement for the range of 50m, but I think the reaction time for the biker will be lower.
Personally I think that you would be better off teaching your kids to ride their bikes in a more responsible manner such that there is no risk of an impact.
If they cannot see whether or not a vehicle is approaching then they should simply not enter the area
Good point, but you can imagine that the alternative is to suck them into videogames.
Beside that, the street is not trafficated that much. Just one or two cars pass in an hour.
And finally, as engineer I can not surrender: By the way this is an engineering forum, not end educational one :).
The alternative is certainly not to suck them into video games, rather it is to teach them to ride their bikes safely which is certainly a skill they will need when they venture further afield.
Can you draw a picture of the roadway that the kids/cars are using... and where you see there are blind spots. It will help with determining possible solutions.
But, it's not a good idea for another reason, the kids will begin to depend on it. It won't always work, then its possible failure could lead to an accident. Then how you would you feel?
Ok, let's recast the problem without mentioning kids or education, ok?
Is it possible to build a DIY system like that? Detection of vehicle behind the wall?
It is just a challenge.
I think a valid and complex solution would be building a phased array with ultrasound to scan the area and report obstacle. The scanner could be mounted in the middle of the grayed street...but I think it is too complex..
@giusepped
Nothing that you have flagged to the moderators is worthy of our intervention. If you don't like the answers you are getting then please reply politely to the ones you don't think are helpful thanking the person for their advice and explaining why the advice isn't what you were looking for.
You didn't like my suggestion? A vehicle's wheels make a big low frequency noise in the ground. All you need to do is pick it up.
Or, radar. It's pretty reliable. There is no magic solution, the application is so common (apart from your particular need) that if there was, it would be available in your local retail store.
You're an engineer. Why not explain to us what problems you are facing. We love to hear engineering talk.
The problem is: detect a vehicle behind a wall and send alerts to a number of receivers.
Your idea is very interesting, but I would make some signal processing in order to separate the audio from noise. Is Arduino right for that?
I think that maybe the cheapest solution would be ultrasound, although the range is not that high.
The vehicle will not be behind a wall if you mount the detector on the front of the house, but I still think that your proposal is questionable at best
Overhead laser scanner or ultrasonics would work. I'd use overhead TOF sensors placed at a stationary distance aimed at the road. When the TOF sensors detect a different range then possible car entry into the area. One sensor at each end minimum hooked to a solar powered wireless Microcontroller transmitting to a centeral unit that could ignite the bells and whistles.
I think I can put them in the middle wall...